Ditched the copy-to-scratch-RAM step for drawing textured faces, which apparently is no longer needed to run on real hardware.

Simpler code, less work to do, better performance. An all-round win.

draw.h

@@ -146,10 +146,9 @@ static INLINE void draw_triangle_textured(STVECTOR *verts, u_short tpage, u_long
     ++polyCount;
 }
 
-static INLINE void draw_quadstrip_textured(STVECTOR *verts, u_char numVerts, u_short tpage, u_long *ot)
+static INLINE void draw_quadstrip_textured(const ps1bsp_vertex_t *vertices, const ps1bsp_polyvertex_t *polyVerts, u_char numVerts, u_short tpage, u_long *ot)
 {
-    // Draw the face as a quad strip
-    STVECTOR *v0, *v1, *v2, *v3;
+    const ps1bsp_polyvertex_t *v0, *v1, *v2, *v3;
     u_char i0, i1, i2, i3;
     u_char head = 0;
     u_char tail = numVerts;
@@ -168,23 +167,22 @@ static INLINE void draw_quadstrip_textured(STVECTOR *verts, u_char numVerts, u_s
         i2 = --tail;
         i3 = head++;
 
-        v0 = &verts[i0];
-        v1 = &verts[i1];
-        v2 = &verts[i2];
+        v0 = &polyVerts[i0];
+        v1 = &polyVerts[i1];
+        v2 = &polyVerts[i2];
+        v3 = &polyVerts[i3];
 
-        // Naively draw the quad with GTE, nothing special or optimized about this
-        gte_ldv3(v0, v1, v2);
+        // Transform the first three vertices
+        gte_ldv3(&vertices[v0->index], &vertices[v1->index], &vertices[v2->index]);
         gte_rtpt();     // Rotation, translation, perspective projection
 
-        // Draw a flat-shaded untextured colored quad
+        // Draw a gouraud shaded textured quad
         POLY_GT4 *poly = (POLY_GT4*)mem_prim(sizeof(POLY_GT4));
         setPolyGT4(poly);
         gte_stsxy3_gt3(poly);
 
-        v3 = &verts[i3];
-
         // Transform the fourth vertex to complete the quad
-        gte_ldv0(v3);
+        gte_ldv0(&vertices[v3->index]);
         gte_rtps();
         gte_stsxy(&poly->x3);
 
@@ -194,20 +192,20 @@ static INLINE void draw_quadstrip_textured(STVECTOR *verts, u_char numVerts, u_s
         poly->tpage = tpage;
 
         // Vertex color lighting
-        poly->r0 = poly->g0 = poly->b0 = (uint8_t)v0->pad;
-        poly->r1 = poly->g1 = poly->b1 = (uint8_t)v1->pad;
-        poly->r2 = poly->g2 = poly->b2 = (uint8_t)v2->pad;
-        poly->r3 = poly->g3 = poly->b3 = (uint8_t)v3->pad;
+        poly->r0 = poly->g0 = poly->b0 = (uint8_t)v0->light;
+        poly->r1 = poly->g1 = poly->b1 = (uint8_t)v1->light;
+        poly->r2 = poly->g2 = poly->b2 = (uint8_t)v2->light;
+        poly->r3 = poly->g3 = poly->b3 = (uint8_t)v3->light;
 
         addPrim(ot, poly);
         ++polyCount;
     }
 }
 
-static INLINE void draw_quadstrip_water(STVECTOR *verts, u_char numVerts, u_short tpage, u_long *ot)
+static INLINE void draw_quadstrip_water(const ps1bsp_vertex_t *vertices, const ps1bsp_polyvertex_t *polyVerts, u_char numVerts, u_short tpage, u_long *ot)
 {
     // Draw the face as a quad strip
-    const STVECTOR *v0, *v1, *v2, *v3;
+    const ps1bsp_polyvertex_t *v0, *v1, *v2, *v3;
     u_char i0, i1, i2, i3;
     u_char head = 0;
     u_char tail = numVerts;
@@ -225,25 +223,22 @@ static INLINE void draw_quadstrip_water(STVECTOR *verts, u_char numVerts, u_shor
         i2 = --tail;
         i3 = head++;
 
-        v0 = &verts[i0];
-        v1 = &verts[i1];
-        v2 = &verts[i2];
+        v0 = &polyVerts[i0];
+        v1 = &polyVerts[i1];
+        v2 = &polyVerts[i2];
+        v3 = &polyVerts[i3];
 
-        // Naively draw the quad with GTE, nothing special or optimized about this
-        gte_ldv3(v0, v1, v2);
+        // Transform the first three vertices
+        gte_ldv3(&vertices[v0->index], &vertices[v1->index], &vertices[v2->index]);
         gte_rtpt();     // Rotation, translation, perspective projection
 
-        // Draw a flat-shaded untextured colored quad
+        // Draw a flat-shaded textured quad
         POLY_FT4 *poly = (POLY_FT4*)mem_prim(sizeof(POLY_FT4));
         setPolyFT4(poly);
-        gte_stsxy0(&poly->x0);
-        gte_stsxy1(&poly->x1);
-        gte_stsxy2(&poly->x2);
-
-        v3 = &verts[i3];
+        gte_stsxy3_ft3(poly);
 
         // Transform the fourth vertex to complete the quad
-        gte_ldv0(v3);
+        gte_ldv0(&vertices[v3->index]);
         gte_rtps();
         gte_stsxy(&poly->x3);
 

world.c

@@ -167,47 +167,23 @@ static void world_drawface_textured(const world_t *world, const ps1bsp_face_t *f
         return;
 
     // Draw textured, vertex colored polygons
-    STVECTOR *verts = (STVECTOR*)(scratchpad + 256);
-    ps1bsp_texture_t *faceTexture = &world->textures[face->textureId];
+    const ps1bsp_texture_t *texture = &world->textures[face->textureId];
     const ps1bsp_polygon_t* poly = &world->polygons[face->firstPolygon];
 
     if (face->flags & SURF_DRAWWATER)
     {
         for (u_char polyIdx = 0; polyIdx < face->numPolygons; ++polyIdx, ++poly)
         {
-            ps1bsp_polyvertex_t *polyVertex = &world->polyVertices[poly->firstPolyVertex];
-            STVECTOR *curVert = verts;
-            for (u_char vertIdx = 0; vertIdx < poly->numPolyVertices; ++vertIdx, ++polyVertex, ++curVert)
-            {
-                const ps1bsp_vertex_t *vert = &world->vertices[polyVertex->index];
-                curVert->vx = vert->x;
-                curVert->vy = vert->y;
-                curVert->vz = vert->z;
-                curVert->u = (u_short)polyVertex->u;
-                curVert->v = (u_short)polyVertex->v;
-            }
-
-            draw_quadstrip_water(verts, poly->numPolyVertices, faceTexture->tpage, ot);
+            ps1bsp_polyvertex_t *polyVertices = &world->polyVertices[poly->firstPolyVertex];
+            draw_quadstrip_water(world->vertices, polyVertices, poly->numPolyVertices, texture->tpage, ot);
         }
     }
     else
     {
         for (u_char polyIdx = 0; polyIdx < face->numPolygons; ++polyIdx, ++poly)
         {
-            ps1bsp_polyvertex_t *polyVertex = &world->polyVertices[poly->firstPolyVertex];
-            STVECTOR *curVert = verts;
-            for (u_char vertIdx = 0; vertIdx < poly->numPolyVertices; ++vertIdx, ++polyVertex, ++curVert)
-            {
-                const ps1bsp_vertex_t *vert = &world->vertices[polyVertex->index];
-                curVert->vx = vert->x;
-                curVert->vy = vert->y;
-                curVert->vz = vert->z;
-                curVert->u = (u_short)polyVertex->u;
-                curVert->v = (u_short)polyVertex->v;
-                curVert->pad = polyVertex->light;
-            }
-
-            draw_quadstrip_textured(verts, poly->numPolyVertices, faceTexture->tpage, ot);
+            ps1bsp_polyvertex_t *polyVertices = &world->polyVertices[poly->firstPolyVertex];
+            draw_quadstrip_textured(world->vertices, polyVertices, poly->numPolyVertices, texture->tpage, ot);
         }
     }
 }